This marigold flower for nematode control is effective for control of root knot and other plant-parasitic nematodes in cropping systems, and it can be utilized in the home garden as well. Marigolds used for this purpose are typically planted as a cover crop to suppress nematodes prior to planting the crop or garden. The marigolds are tilled under after a certain length of time. In long-season climates, crops can be planted the same season. In cooler climates, marigolds are used in rotation with the regular crop from one season to the next.